Question: ${2 \div 0.4 = {?}}$
Explanation: $ {2 \div 0.4 = 2 \div \dfrac{4}{10}} $ $ {\phantom{2 \div 0.4} = 2 \div \dfrac{2}{5}} $ Dividing by a fraction is the same as multiplying by the reciprocal of the fraction. $ {2 \div \dfrac{2}{5} = 2 \times \dfrac{5}{2}} $ $ {\phantom{2 \div \dfrac{2}{5}} = \dfrac{2 \times 5}{2}} $ $ {\phantom{2 \div \dfrac{2}{5}} = \dfrac{10}{2}} $ $ {\phantom{2 \div \dfrac{2}{5}} = 5} $